This How to guide come in handy when you need to change the hostname of Ubuntu server machine. To change hostname in Ubuntu server, login to root user or a root privileged user and run the below command.
For root privileged users
sudo vi /etc/hostname
And now type the new hostname of your Ubuntu 14.10 server and perform a reboot to take effect the new hostname.
You can also change the server’s hostname temporarily by running the below command. Note the new hostname is a temporary one, and will revert to the default/old hostname after a reboot
<span style="color: #008000;">sudo hostname <NewHostname></span>
To view the hostname of any Ubuntu machine, run te below command